Apparatus for assembling commutator-bars



(No Model.)

7 S. H. SHORT.

APPARATUS FOR ASSEMBLING GOMMUTATOR BARS.

' No. 593,282. Patented Nov. 9,1897.

UNTTED STATES PATENT Trice.

SIDNEY I-I. SHORT, OF CLEVELAND, OHIO.

APPARATUS FOR ASSEMBLlNG COMMUTATOR-BARS.

SPECIFICATION forming part of Letters Patent No. 593,282, dated November 9, 1897.

Application filed April 26, 1897. Serial No. 633,879. (No model.)

To wZZ whom it may concern:

Beitknown that I, SIDNEY H. SHORT, a citizen of the United States, residing at Oleveland, in the county of Ouyahoga and State of Ohio, have invented a new and useful Apparatus for Assembling Oommutator-Bars, of which the following is a specification.

This invention relates to apparatus for assembling commutator-bars.

The object of the invention is to provide means whereby the commutator-bars of electric machines may be assembled rapidly, uniformly, and efficiently,whereby the periphery or external surface of the ring or cylinder formed by the bars when assembled will not require material reduction, and whereby variation in the transverse width of the commutator-bars is avoided.

The invention consists substantially in the construction, combination, location, and relative arrangement, all as will be more fully hereinafter set forth, as shown in the accompanying drawings, and finally specifically pointed out in the appended claims.

Referring to the accompanying drawings and to the various views and reference-signs appearing thereon, Figure 1 is a plan view of an apparatus embodying my invention. Fig. 2 is a transverse sectional view of the same with the commutator-bars assembled therein. Fig. 3 is a view in plan of the split holderring. Fig. 4 is an edge View of the same. Fig. 5 is a detached detail view, slightly in perspective, of a commutator-bar.

In the construction and assembling of the commutator-bars of electric machines it is a matter of great importance that the external surface or periphery of the ring or cylinder formed by the commutator-bars when assem bled be absolutely cylindrical in order to avoid breaks or unevenness in the surface with which the brushes contact. l-leretofore it has been necessary after the commutatorbars are assembled to reduce or turn down the outer surface or periphery of the ring formed thereby in order to produce an absolutely cylindrical surface and to remove any unevenness in the extent of projection of the outer edges of individual bars. This practice necessarily resulted in causing variations in the transverse width of the several bars, a feature which is objectionable and which should be avoided. Moreover, it has heretofore been difficult to rapidly assemble the commutator-bars with sufficient compression or contraction of the diameter of the ring or cylinder formed thereby when assembled.

It is the purpose of my invention to avoid the objections noted and to produce an apparatus whereby the commutator-ring may be built up rapidly and efficiently and whereby the outer edges of the commutator-bars all lie in the same cylindrical surface and do not require subsequent reduction or turning down.

In the accompanying drawings, illustrating apparatus for accomplishing my purpose, reference-signs A B designate, respectively, two separable halves orparts of a cylindrical ring or casting rabbeted on the interior surface thereof, as at O, and also provided with a groove D in the interior surface thereof. The two halves or sections A B of the ring or casting are provided with flanges E, through which suitable bolts may be passed, whereby said halves or sections may be securely bolted together, and when bolted together the rabbet O and groove D of the one section exactly registers with the rabbet and groove of the other section end for end.

Reference-sign F designates a ring of castiron or other suitable material transversely split upon a bevel or incline, as at G, and presenting a smooth inner surface and having a fiangeH projecting from the periphery thereof. By pressing the ends of this split ring together sufficiently the diameter of said ring may be contracted to a point enabling said ring to be received within the assembled half-sections A B, and with the flange H of said split ring arranged in the groove D of said half-sections. With the split ring thus arranged the commutator-bars are assembled therein. These bars are of uniform shape throughout and are exact duplicates of each other, and they comprise the body J, having the dovetail projection K to receive the end rings and heads, and with the projecting portion L to connect with the armature-windings. The commutator-bars are built up inside the ring F, said bars being arranged radially therein with the dovetail projections K projecting toward the center, the rabbet O accommodating the lead projections L.

Thus the ring is filled up, strips of insulation alternating with the commutator-bars until finally the ring of bars is completed.

The operation of compressing the assembled ring now begins. This is accomplished by tapping set-screws M at various and suitable points through the half sections of clamping-ring A B, with their inner ends impinging against the periphery or the external surface of ring F. These set-screws are arranged on both sides of the flange II, as clearly shown in Fig. 2. By successively turning up on these set-screws all the way peripherally around the clamping-ring the diameter of the ring or cylinder formed by the commutator-bars is gradually contracted and in a manner to tightly compress the commutatorbars flatwise against each other, and this, too, without disturbing the relative edgewise position of the commutator-bars, and hence when the compressing operation is finally completed the outer edges of the several commutator-bars all lie in the same cylindrieal surface, and hence do not require turning down after being removed from the clamping-ring. By splitting the ring F on a diagonal line, as shown and referred to above, I insure that the outer edge of every commutator-bar J has a bearing against the inner surface of the ring F, and by successively turning up on the set-screws M all the way around the clampin g-rin g I constantly maintain the inner surface of split ring F, and consequently the external surface or periphery of the ring formed by the commutator-bars and interposed insulation, absolutely cylindrical. \Vhen the compression and contraction is completed, the mica end rings and the commutator-heads are clamped upon the colnmutator-ril'ig in the usual or ordinary manner and the commutator is complete.

From the foregoing description it will be readily seen that if it is desired to bore out the internal surface of the commutator-rin g, or to reduce or turn down the end surface of the same, the circular casting A B, with the split ring F and eonnmitator-ring arranged and circularly compressed therein, may be mounted upon the face-plate of a lathe in which such boring, facing, or turning down may be accomplished, thusinsuring absolute uniformity in the work.

Duriu g the compressing and contracting operation it is desirable to subject the commutator-ring to heat in order to expand any air that may be contained in the joints or airholes in or between the mica strips employed as insulation, thereby expelling the air' during the compression, and hence securing an absolutely solid ring. By the application of heat I also am enabled to expel or squeeze out any varnish that may be used for holding the mica strips together.

Having now set forth the object and nature of myinvention and a form of apparatus embodying the same, and having described the function and purpose thereof, I desire it to be understood that I do not wish to be limited or confined to the exact details of con struction and arrangement shown and described, as many changes and variations therefrom would readily suggest themselves to persons skilled in the art and still fall within the spirit and scope of my invention; but

\Vhat I do claim as new and useful. and of my own invention, and desire to secure by Letters Patent of the United States, is

1. In an apparatus for building up OOlnliltb tators a diagonally-split and compressible spring strap or hoop in which the commuta tor-bars are assembled radially, a casting ar ranged to receive said split ring, and means for contracting said strap or hoop within said casting, as and for the purpose set forth.

2. In an apparatus for building up commutators, a diagonally-split ring in which the commutator-bars are assembled to form the commutators, a circular casting adapted to receive said split ring, and a plurality of su itably-spaeed set-screws tapped through said casting and arranged to impinge upon said split ring whereby the ends formed. by diagonally splitting said ring may be gradually brought together thereby gradually contract ing the diameter of said ring within said castin g, as and for the purpose set forth.

3. In an apparatus of the class d escribet'l asplit ring having a peripheral flange, and in which the commutator-bars are adapted to be assembled, and a casting adapted to receive said ring and having a groove adapted to receive said. flange, and set-screws tapped through said casting and adapted when turned up to contract the diameter of said split ring, as and for the purpose set forth.

4-. In an apparatus of the class described a split ring in which the commutator-bars are adapted to be assembled, in combination with a sectional casting adapted to receive said split ring, means for securing the sections of said casting together and means for gradually contracting the diameter of said split ring, as and for the purpose set forth.

5. In an apparatus of the class described, asplit ring in which the commutater-bars are adapted to be assembled, in combination with a circular casting having a rabbet, said casting adapted to receive said split ring, the leads of the eomnnltator-bars arranged to project into said rabbet, and means for con.- tracting the diameter of said split ring, as and for the purpose set forth.

(3. In an apparatus of the class described asplit ring having a peripheral flange and. in which the commutator-bars are adapted to be assembled, in combination with a circular casting in which said ring is adapted to be received, said casting provided with a groove to receive the flange on said split ring, and. means for compressing said split ring, as and for the purpose set forth.

7. In an apparatus of the class described, a split ring in which the commutator-bars are IIO adapted to be received and assembled, in combination with a circular casting made in half-sections adapted to be bolted together, said casting adapted to receive said ring, and set-screws tapped through said casting and adapted to impinge on said ring, as and for the purpose set forth.

8. In an apparatus of the class described, a split ring in which the commutator-bars are adapted to be assembled, in combination with a casting or encircling ring adapted to receive said split ring, and set-screws tapped through said encircling ring, and impinged against the exterior surface of said split ring, the whole adapted to be subjected to heat where- SIDNEY H. SHORT.

Attest:

W. M. CORD, S. E. DARBY. 

